A pressure switch is a device used in various sectors, all having the requirement of using a switch which is piloted by a pressure.
The present invention relates to a special application of a pressure switch in the field of water-cleaning machines, and more precisely for activating a water gun, but it could be used in any application where installation of a pressure switch operating cyclically is required.
As is known, pressure switches are for activating or deactivating an electric circuit in accordance with a hydraulic pressure and can be used as control components to initiate, according to a pressure, a work cycle or to consent to continuation of operations or sequences, or stop them.
The prior art includes pressure switches of two types: with a piston or with a tubular spring.
Generally each piston pressure switch is constituted by an external body which internally has a stem which functions as an actuator, connected to a box containing a micro-switch, with an end of the stem being close to the micro-switch and the opposite end of the stem being connected to a hose for fluid delivery.
The fluid pressure acts on the piston, contrasted by an elastic means. If the hydraulic force generated by the liquid being delivered and operating on the piston exceeds the elastic force, the piston slides and touches the micro-switch, and the contacts commutate. When the fluid pressure is reduced below the threshold pressure level, i.e. the calibrated level of the pressure switch, the elastic force overcomes the hydraulic force and the piston returns into the neutral position, switching off the micro-switch.
The prior art, briefly described above, has been the subject of critical analysis because of intrinsic limitations and drawbacks connected with it.
Considering that the pressure switch is often mounted as a safety component, a high degree of durability and reliability is required of it.
An important aim of the invention is to provide a pressure switch in which the impact between the piston and the micro-switch is considerably damped, thus preventing damage of the circuit part on which the pressure switch acts.
A further important aim of the invention is to provide a device which consequently to the translating alternating cycle of the piston, prevents lacerations of the seals even after long operating periods.
A further important aim of the invention is to provide a pressure switch which guarantees equal performance in traditional assembly typologies but which can also be mounted in extreme positions, for example directly on the pump head, which is where the pressure gradients are highest.
The technical objective and specified aims are all attained by a pressure switch which is characterised in that it comprises one or more of the technical solutions described herein below.